The Effectiveness of the Interventions to Reduce Sound Levels in the ICU: A Systematic Review

Actual versus perceived noise levels among critical care nurses and their related adverse effects: A cross-sectional study

BACKGROUND

Critical care nurses should help in reducing noise to improve the well-being of patients and health care providers.

AIM/S

To measure actual noise levels in intensive care units, identify nurses' perceived irritation levels of noise sources and examine the impact of noise on nurses' work performance and well-being.

STUDY DESIGN

This cross-sectional study was conducted from January to April 2023 at a teaching hospital's six intensive care units. It involved three phases: mapping locations for noise measurement, actual noise measurements in decibels and a cross-sectional survey to identify nurses' perceptions and the adverse effects of noise. Actual noise was measured between patients' beds, nursing stations and beside 16 noise sources for 7 days 24 h a day. For nurse perceptions, the mean of perceived irritation levels by a Likert scale for each noise source was calculated to present perceived noise levels. Ranking of noise sources according to the actual measured and perceived irritation by nurses was done based on mean values. Curve estimation regression test was used to predict the relationship between actual and perceived noise and stepwise multiple linear regression identified factors associated with noise adverse effects.

RESULTS

The mean noise level in the intensive care units was 65.55 dB. Nurses perceived mechanical ventilator alarms as the most irritating noise. However, the mean noise measurements showed that conversations among colleagues were the primary source of noise. There was no significant predictive relationship between the actual and perceived noise. Nurses reported feeling distressed, irritable, fatigued and less productive due to noise.

CONCLUSIONS

There was a discrepancy between actual and perceived noise levels by nurses. Perceived noise levels had more impact on nurses than actual noise.

RELEVANCE TO CLINICAL PRACTICE

By incorporating both objective measurements and subjective perceptions into efforts aimed at reducing noise, health care providers can create quieter intensive care units.

Noise exposure among staff in intensive care units and the effects of unit-based noise management: a monocentric prospective longitudinal study

BACKGROUND

Intensive care units (ICUs) are often too noisy, exceeding 70-80 dBA, which can have negative effects on staff. The corresponding recommendation of the World Health Organization (average sound pressure level below 35 dBA) is often not achieved. To date there is a lack of intervention studies examining the extent to which unit-based noise management in ICUs contributes to a reduction in noise exposure for the staff. The study therefore aims to provide answers to 1) how unit-based noise management sustainably reduces the subjective noise exposure among staff, and 2) how this intervention affects other noise-related topics.

METHODS

We performed a monocentric prospective longitudinal study with three measurement points in a German university hospital in three ICUs. We collected data from different healthcare professionals and other professional groups between October 2021 and August 2022 using an online questionnaire. Data were analyzed using descriptive and inference statistics.

RESULTS

A total of n = 179 participants took part in the surveys. The majority of participants were nurses or pediatric nurses. Most participants worked more than 75% full-time equivalent. Staff on the three ICUs reported high levels of noise exposure. No significant changes in noise exposure over time were observed. Participants were already aware of the topic and believed that a behavior change could positively influence the noise environment.

CONCLUSIONS

This study provides an initial insight into how a unit-based noise management could contribute to a reduction in the subjective noise exposure among staff in ICUs. The results of this study highlight the importance of this topic. Future studies should aim to research aspects of adherence and their facilitators or barriers, which promote the sustained implementation of noise-reducing measures by staff.

TRIAL REGISTRATION

German Clinical Trials Register (DRKS): DRKS00025835; Date of registration: 12.08.2021.

Decibel Decisions: The Concept of Intracranial Aneurysm Surgery With a Decibel Meter on Two Surgical Cases

The present cases were used to investigate the reliability of the intraoperative decibel meter as an objective method of clipping efficiency in cerebral aneurysm surgery and to assess the impact of this method on the surgical procedure itself. Different methodologies have been developed and applied to directly or indirectly evaluate the placement of a clip, for example, intraoperative digital subtraction angiography (DSA), intraoperative micro-Doppler ultrasonography, and, more recently, indocyanine green (ICG). We included two patients with a previously non-treated unruptured brain aneurysm. In both patients, intraoperative micro-Doppler was used in combination with a decibel meter app. Here, we present the cases of two patients. In patient one, the pre-clipping average sound level/equivalent continuous sound pressure level (Avg/Leq) was 96.7 dB, while the post-clipping Avg/Leq was 94.4 dB, indicating a reduction in sound level after clipping. Similarly, the pre-clipping time-weighted average noise level (TWA) was 1.2%, while the post-clipping TWA was 0.5%, indicating a decrease in exposure dose after clipping. In patient two, the average sound level for the post-clipping measurement (94.2 dB) was higher than the pre-clipping measurement (93.5 dB), but the difference was not statistically significant. These cases indicate the potential for using sound measurements as a reliable indicator of adequate aneurysm occlusion during clipping procedures. Further research is needed to confirm these findings.